My SBE II came with five, and they are the least common type, the Crio chokes. I looked it up, the m2 uses the Crio tubes also. The standard choke tubes also fit Beretta guns, and are easier to find. The Crio tubes are not very difficult to find, you just see alot more of the standard tubes.
You will have to check how many each gun comes with when you go to buy. I heard that Benelli wasn't sending 5 choke sets anymore, but I could be wrong.